* New superbug genes now found in bacteria around world
* NDM-1 easily swapped by different germ species
By Maggie Fox, Health and Science Editor
WASHINGTON (Reuters) - A little loop of genes that
give bacteria the power to resist virtually all known
antibiotics is spreading quickly and likely to cause doctors
headaches for years to come, an expert predicted Wednesday.
They come on the equivalent of a genetic memory stick -- a
string of genes called a transmissible genetic element.
Bacteria, unlike higher forms of life, can swap these gene
strings with other species and often do so with wild abandon.
This one is called New Delhi metallobeta-lactamase 1 or
NDM-1 for short and Dr. Robert Moellering of Harvard Medical
School and Beth Israel Deaconess Medical Center in Boston
predicts it will cause more trouble in the coming years.
"What makes this enzyme so frightening is not only its
intrinsic ability to destroy most known beta-lactam antibiotics
but also the company it keeps,' Moellering wrote in a
commentary in the New England Journal of Medicine.
First described in 2008, NDM-1 has been found in a wide
variety of bacterial types, including the Enterobacteriaceae
family, klebsiella and Escherichia coli, all of which are
common and cause a range of infections.
British researchers reported in August infections involving
NDM-1 had been found in patients in Bangladesh, India, Pakistan
and Britain. [ID:nLDE67A0O1]
"In addition, isolates of Enterobacteriaceae-containing
NDM-1 have now been characterized in the United States, Israel,
Turkey, China, India, Australia, France, Japan, Kenya,
Singapore, Taiwan, and the Nordic countries," Moellering
Antibiotic-resistant bacteria are nothing new -- virtually
all strains of the common Staphylococcus bacteria are now
resistant to penicillin. Almost as soon as penicillin was
introduced in the 1940s, bacteria began to develop resistance
to its effects, prompting researchers to develop many new
generations of antibiotics.
But their overuse and misuse have helped fuel the rise of
drug-resistant "superbugs." The U.S. Centers for Disease
Control and Prevention says most infections that people get
while in the hospital resist at least one antibiotic.
For example, half of all Staphylococcus aureus infections
in the United States are resistant to penicillin, methicillin,
tetracycline and erythromycin. Methicillin-resistant staph
aureus or MRSA killed an estimated 19,000 people in the United
States alone in 2005.
NDM-1 resists many different types of antibiotic. In at
least one case, the only drug that affected it was colistin, a
toxic older antibiotic.
"Thus far, the majority of isolates in countries throughout
the world can be traced to subjects who have traveled to India
to visit family or have received medical care there,"
"However, the ability of this genetic element to spread
rapidly among Enterobacteriaceae means that there will almost
certainly be numerous secondary cases throughout the world that
are unrelated to travel to the Indian subcontinent."
Experts have been warning for years that poor hospital
practices and the overuse of antibiotics spread dangerous
bacteria, but practices are changing only slowly.
"The fact that there is widespread nonprescription use of
antibiotics in India, a country in which some areas have less
than ideal sanitation and a high prevalence of diarrheal
disease and crowding, sets the ideal stage for the development
of such resistance," Moellering wrote.
(Editing by Cynthia Osterman)
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